Multi-well sample plates which comprise several separate sample wells are widely used as test plates for in vitro analysis. Said plates can be produced for example by vacuum thermoforming (deep drawing) from a transparent plastic sheet and they have for example eight rows of wells arranged in twelve columns. These plates can be used especially for preparing typically low energy beta radiation emitting liquid scintillation samples. Unfortunately, these samples must first be transferred into liquid scintillation counting vials, because existing liquid scintillation counters cannot count samples directly from this kind of multi-well sample plates.